Manufacture of modified rosin



. Patented Feb. 16, 1943 2,311,200 MANUFACTURE OF MODIFIED ROSIN LaszlAuer, East Orange, N. J. I No Drawing. Application April 1, 1941, SerialNo.

In Hungary May 19, 1926 12 Claims. (01. 260-106) This invention relatesto the manufacture ,of modified ,organic lsocolloids and it comprisesprocesses of modifying organic isocolloids, particularly natural resinsand other resinous organic isocolloids, with the aid of metal salts asthe modifying agent, wherein a minor amount of a metal salt is dispersedor dissolved in the resin or other resinous organic isocolloid toproduce the desired modification thereof, the mixture beingadvantageously heated under reduced pressure or in vacuo to facilitatethe incorporation of the said modifying agent and the modification ofthe organic isocolloid, and it also comprises the modified resins andother modified organic isocolloids so obtained, said modified productsbeing useful in making plastics and plastic and liquid coatingcompositions and containing an amount of modifying agent dispersedtherein sumcient to substantially and advantageously modify theirproperties, and it further comprises plastic compositions and liquidcoating compositions containing such modified organic isocolloidproducts, particularly those containing modified resin products; all asmore fully hereinafter set forth and as claimed.

In my prior applications more fully identified post, I have describedprocesses of modifying the properties of organic isocolloids, such asfatty oils, resins, etc. particularly their physical properties such asviscosity, melting point, solubility, etc. as well as other propertiesthereof. As

\ stated in my prior applications, the modified organicisocolloidmaterials obtained by the processes described therein, areuseful for various purposes; the modified products so obtained fromfatty oils, resins, etc. being useful and advantageous in makingvarnishes,lacquers, and other liquid coating compositions, as well as inmakin plastic compositions.

The present invention also relates to such processes. And thisapplication is directed to certain of the processes described in saidprior applications, as hereinafter described; it being a continuation-in-part of my copending, prior ap-- plications as all more 'fullysetforth post.

-'Ihis.application is a continuation-impart of modifying agents areemployed in minor amounts my copending, prior application Ser. No.318,650,

filed Feb. 12; 1940 (now Patent 2,298,270). That of my prior applicationSer. No. 143,786,- filed Oct. 23, 1926 (now Patent No. 2,189,772) and ofthe various continuations thereof previously filed by me, particularlySer. No. 359,425, filed April 30, 1929 (now Patent No. 2,213,944) andSerial No. 446,172, filed April 21, 1930 (now Patent No. 2,213,943;.said Ser. No. 143,786 being the parent application of all said priorapplications.

applicationis, in turn, a jcontinuation-in-part.

In my prior applications, listed ante, I have disclosed various methodsof modifying organic isocolloid materials, such as fatty oils, resins,etc., using many different modifying agents. As there disclosed, mygeneric invention relates to processes for the modification of thephysical properties of organic isocolloids and to the modified organicisocolloid products o btained. By the terms "organic isocolloids andorganic isocolloid materials I mean organic isocolloid substanceswherein the dispersed phase and the dispersion medium of the colloidalsystem thereof areboth of the same chemical composition but in adifferent state, That is, such organic isocolloids are mixtures ofchemically similar organic carbon compounds wherein one or more of thosecompounds is dispersed or dissolved'in the others, which serve as thedispersion medium of this isocolloid system.

As disclosed in my said prior applications, -I have found that bydispersing or dissolving various modifying agents in fatty oils, resinsand other organic isocolloid materials, I obtain new modified organicisocolloid products having altered properties which are useful in thecommercial and industrialarts as shown therein. The

and are organic or inorganic compounds which are electrolytes or polarcompounds capable of infiuencingthe modification of the isocolloidsubstances. In these applications many illus- 'trative examples of thepractice of my generic invention'or discovery are disclosed.

The various modifying agents or polar compounds and the severalprocedures disclosed in said prior applications are useful in thepractice of the present invention.

According to the present invention I treat natural' and synthetic esinscontaining high molecular acids and ob ain valuable modified resinproducts.v And natural resins may be used with advantage in my presentprocesses. Examples of such natural resins are: gum and wood rosins,copais (preferably premoltenor fused), shellac, et'c. Examples of thecopal-type fossil gums are:

' East India gum, Manilla copal, Congo copal, kauri copal', etc. Thecopais should first be fused or run, to obtain a reversibly fusibleproduct, and then the fused or molten copal (run copal) treatedaccording to the present invention.

Likewise, synthetic resins may be modified by the present processes. Infact, I have found that most synthetic resins are inherently organicisocolloids. That is, they are mixtures of chemically similar resinouscompounds in which some of the resinous compounds are dissolved ordispersed in the remainder of the resinous mixture.

used, such as phthalic acid, adipicanhydride, sebacic anhydride, maleicanhydride and other dibasic acids and their anhydrides. Again, otherpolyhydric alcohols, such as those mentioned ante, are sometimes used inlieu of all or part of the glycerine. Further, such polyhydricalcoholpolybasic acid resin can be made in other ways than by directesterification of the alcohol with the acids. However, irrespective ofthe way in which they are made, these resins are complex; resinousesters of -a polyhydric alcohol with a polybasic acid and a mono-basicacid capable of ucts obtained. However, certain types of syntheticresins may be used with advantage in the practice of this invention.

As stated in my prior applications synthetic resins made from orcontaining natural resins, as a component thereof, are advantageousstarting materials in the present processes. They, like the naturalresins themselves, may be readily modified in accordance with my presentinvenresins, including those containing the natural tion.

The synthetic resins containing natural resins, such as rosin, etc.,chemically combined in the resinous complex, give valuable modifiedresins, by the present processes. For instance, the res inous estersobtained by esterifying natural resins. with polyhydric alcohols areadvantageous starting materials in this invention. The best known (andprobably the simplest) of such resin esters is the so-called ester gum.Commercially, ester gums are usually made by esterifying rosin withglycerine. Such ester gums or rosin glycerides are .well known varnishresins and are widely used in making various varnishes. By

. properties.

the present invention, any of the commercial ester gums can be readilymodified to improve their properties for such purposes.

Likewise, other resinous esters of glycerine and natural resins, such ascopals, etc.,.may also be modified by my methods. Also,the resinousesters obtained by esjzerifying rosin, copals and other acid naturalresins with other polyhydric alco-j hols, such as glycols,pentaerythritol, mannitol. sorbitol, etc., are useful as the startingmateria and give good modified resins.

In fact, I have found that resinous esters of polyhydric alcohols,generally, can be modified by my present processes. Those in which thepolyhydric alcohol is esterified in part by 'a natural resin and in partby another acid, either used in making varnishes and othercoating'compositions. They may be made by esterify ing glycerine withphthalic anhydride andamonobasic acid capable of imparting dryingproperties to the resulting resin; the'fatty acids of drying oils beingusually employed as such mono-basic acid. However, sometimes rosin orother natural resin acids are used along or in conjunction with saidfatty acids ,in' making such resins. Likewise, in lieu of phthalicanhydride, other polybasic acids or their anhydrides are sometimes resinby my processes.

imparting drying properties to the resinous complex. Any and all of suchresins can be modified by my present processes and good modified resinproducts obtained.

That is, in the practice of this invention, I may use synthetic resinsmade from or containing the acids of natural resins or of fatty oils orboth such as the resinous esters mentioned ante.

Further, by the present invention, I can also modify other syntheticresins containing natural resin as such. For instance, theso-calledresinmodified phenolics or Albertols can also be modified by my presentprocesses to improve their Such phenolic resins are phenol aldehyderesins containing a sufficient amount of natural resins or of estersthereof, to alter their solubility and other properties. They are nowused in making varnishes, particularly the phenol-formaldehyderesinscontaining rosin or other natural resins or their esters with polyhydricalcohols, such as glycerine. In my present invention, any of thesephenolic resins can be advantageously modified with the aid of metalsalts by my processes.

Thus in the practice of this invention, I can use a wide variety ofresins, both natural and synthetic resins, and obtain a Wide range ofmodified resin products useful in making plastic-and liquid coatingcompositions.

.In making such modified resin products by the present invention, theresin is modified by the am of a minor amount of modifying agentaccording to the methods disclosed in my prior applications and thevarious modifying agents, such as metal salts etc. there disclosed maybe employed. In fact, metal salts as a class are particularly useful inmodifying resins by the present processes. And in the practice of thepresent invention, the various metal salts specifically mentioned in myprior applications are advantageous.

In other words", the present invention may be carried out in the samemanner disclosed in any of my prior applications; And in modifying Iresins and resinous organic i'socolloids by the present invention, theproportions of modifying agent and the temperatures, pressures,;etc.disclosed in those applications may be used with advantage. That is, byselecting the modifying agent and the amount thereof and controlling thetemperatures, .pressures and other conditions in my present processes,advantageous modified resin products having the desired properties canbe readily obtained, as shown in my prior applications. I

As further shown in my prior applications, I

' modify the melting point, the viscosity, the solubilitycharacteristics and other properties of the In modifying the meltingpoint of resins, I can produce either an increase or decree se in theirmelting point, as disclosed in my Serial No. 143,786 and the various and318,650 and other continuatlons of said Ser.

No. 143,786. In such processes, the melting point of the resin isdecreased, hence they are liquefaction processes.

However, my invention is manufacture of liquefied {resin products. Forinstance, as disclosed inm-y Ser. No. 143,786, 'I can also increase themelting point and the viscosity of resins by my processes.' As therestated in the case of resins which are solid at room temperature, theincrease in viscosity is indicated by an increase in the point of fusion(melting point), as compared with that of the starting material. Suchmethods for the solidification of resins is further described in myprior applications Ser. Nos. 359,425 and 318,650 and other continuationsof said Ser. No. 143,786. In such processes, the melting point of theresin is increased, hence they are solidification processes.

Infiother words, asshown in my prior applications, the melting point,viscosity and other physical properties of resins and otherorganicisocolloids can be modified by my processes. And in the case of resins,both the viscosity and melt"- ing pointcan be simultaneously modified.with the aid of modifying agents as shown in said prior applications.Further, the modification of the melting point also simultaneouslyinfluences the viscosity of solutions of the modified resins in volatilesolvents. Generally,

That is, by my investigations I have found that viscosity and otherproperties of resins of the kind described, may-'be substantiallyillustrated, by modifying the physical colloidal, structure of suchresins, as disclosed in my prior applications.

And as further disclosed in those applications, the said alterations ormodifications are effected by interaction between the resin substancesand a minor amount of an electrolyte or polar compound as the modifyingagent. 1

' In the broad practice of this invention, the electrolyte or polarcompound may be incorporated in the resinous substance in any suitablemanner. Various methods for doing this are disclosed in my\ priorapplications set forth ante and the methods there disclosed may beemployed in my present Processes.

In general, as described in my Serial No. 143,786, the electrolyte(modifying agent) and the raw or starting material (organic isocolloid)may be mixed cold or melted together or boiled, in the absence of or inthe presence of various additional materials, as described andillustrated in that application and my other prior applications; themixture usually being heated to facilitate the incorporation of themodifying agent and the modification of the starting material. In makingmodified resins by my present processes, itis advantageous to melttogether or fuse the resin and the. modifying agent into a homogeneousmass. That is, themodifying agent may be added to the solid resin, inthe form of not limited to the p small pieces or a powder and themixture heated to a temperature sufficient to fuse theresins to producethe desired modification. Again, the resin may be first melted byheating to a tem-- perature sufiicient to fuse the same and thengradually adding the modifying agent to the fused or molten resin; theheating being continued until the desired modification is obtained.

In either case, the temperature should be sufilcient to fuse the resinand produce a uniform homogeneous modified product.

In general, as disclosed in my prior applications Ser. Nos. 359,425 and318,650, temperatures from 100 to 300C. give satisfactory results inmost cases. Most of the natural resins melt or fuse within thistemperature range and can "be readilymodified by heating to temperaturessufficient to fuse or melt them in the presence of the modifying agent;the heating being continued until the desired modification .is obtained.Only occasionally are temperatures above 300 C. necessary to producesatisfactory results. In

h the harder resins yield solutions having higher viscosities.

such cases higher temperatures may be employed say as high as 350 C. ifnecessary. But in all cases, thetemperature employed should not exceedthat at which the modified resin decom-.

poses. However, generally it is desirable to use lower temperatures;i'.- e., temperatures below 350 C. and this is possible in most cases.instance, most synthetic resins are fusible or thermoplastic within therange given ante and may be modified in substantially thesame way asnatural resins. Of course, syntheticresins having lower melting pointscan be modified at lower temperatures. And in the case of syntheticresins which are liquid at room temperatures, the modifying agent can beincorporated by a simple mixing. That is, in some cases, the startingmaterial and modifying agent can be mixed cold as stated inmy Ser. No.143,786. In such cases, the mixture can be subsequently heated toproduce further modification of the resinous organic i colloid.

- In general, the-temperatures employed in my present processes arebelow those at which the resultant modified resin decomposes and'aresufficient to fuse or melt or otherwise blend the 'mixture into auniform homogeneous modified product. And as stated ante, temperaturesbetween 100 and 300 C. are advantageous in most cases and are usuallyemployed in my present processes for producing modified resins.

That is, I have found that resins under q colloidal transformations whenheated with my modifying agents. I have further' found that the mostvaluable modified resin products are obtained when my processes arecarried out under ease of modification varies with the. natural' originof the resin; these resins beingnatural resins or gums, such as rosin,etc. As further disclosed in that application, I have found'that ofrosins, those of American, French and Spanish origin are more easilyliquefied than the Greek rosins, though the latter undergo considerableimprovement and become suitable for lacquer manufacture. The. followingmodifying agents,

among others, are eminently suitable and useful in the liquefaction ofresins;

Ammonium iodide Magnesium sulphate Magnesium chloride Magnesiumcarbonate Barium thiocyanate Zinc carbonate Zinc bromide Sodium sulphideLead chromate I Potassium dichromate Barium sulphide Cadmium sulphideThe liquefaction is preferably carried out by heat treatment of theresin and modifying agent in vacuo. Usually the temperature employed isbetween 250 and 300 C. and temperatures of 270- to 290 are advantageous.The time required depends on the particular material used and on theliquefaction desired. Generally from 2 to 12 hours heatingwill produceany desired liquefaction with most resins. Thus the conditions formodifying resins are generally similar to those used ante for modifyingfatty oils. Likewise in modifying resins, I may also employ theauxiliaryagents mentioned post. For instance, asdisclosed in Ser. No.359,425, addition of 5 per cent of formic acid to the mixture of resinand metal salt increases the velocity of dissolution of those modifyingagents with consequent improvement of the resulting product. By suchmethods, I convert the natural resins which 'are hard and brittle, intomodified resins which are non-brittle and have a lower fusion or meltingpoint varying with the extent of the liquefaction. Generally theseliquefied resins are plastic, soft resins. In some cases, they areviscous liquid gels,-that is, heavy viscous liquids similar to veryheavily bodied linseed oil. Thus, as stated in my Ser. No. 143,786, softto liquid resins of any intermediate viscosity or hardness can beobtained from solid reshns by my processes.

The present invention accordingly comprises a process whereinmodification of the physical properties of unsaturated organicisocolloids consisting of or containing high molecular acids is effectedby heating under sub-atmospheric pressure with modifying agents of thetype described, characterized by the fact that theisocolloid to bemodified is a resin (for example rosin).

The following examples illustrate the liquefaction of resins by-mymethods.

Example 1 300 parts of rosin (e. g. N-wood rosin) are tional asshown'ante, the resin may be modified withthe zinc.carbonate 'alone, ifdesired. This is shown in the next example.

' Example 2 100 parts of rosin and 5 parts of zinc carbonate are heat:dto between 280 and 290 C. in a 25-29 inch vacuum for 3 to 5 hours.

The modified resin so obtained is a plastic, soft resin having aso-called cold flow. It is useful in making varnishes and likecompositions. Vamishes containing as part of the film-- formingconstituents have increased drying velocity and yield films havingincreased gloss. It is also useful in making printing inks, Further, itis useful in making lacquers, nitrocellulose and other cellulose estercompositions.

Example 3 To parts of hard American rosin are added 8 parts of magnesiumsulphate and 4 parts of formic acid and the mixture heated in a partialvacuum for a few hours, until upon cooling a viscous fluid modifiedresin is obtained. I

In the above examples, the other salts mentioned ante as suitable forthe liquefaction of resins may be used in lieu of those specified inExamples 1, 2 and 3 to obtain still other modinesium sulphate, ammoniumiodide or zinc carbonate. Even if the reaction conditions are notcausing a marked decrease in melting point of the resins the modifiedresins may still show marked improvement as varnish bases. Anotherexample of inorganic salt which causes profound lowering of meltingpoint of rosin under vacuum besides zinc carbonate, ammonium iodide,magnesium sulphate and others, is

lithium carbonate.

The different modifying. agents yield somewhat different products withregard to color, viscosity (plasticity), and also when applied inprotective coatings they differ in rate of drying,

elasticity of the'films and-water and weather resistance of the coatingsobtained.

Also, by these methods, I can modify syn-. thetic resins containing saidnatural resins, such as ester gums, rosin modified phenolic or alkydresins, etc., the ester gums and alkyd resins being esters of polyhydricalcohols with organic acids including fatty acids or resin acids orboth, and being generally glycerin esters, they ,are organic isocolloidsof a type somewhat analogous to the fatty oils, particularly heavilybodied fatty oils.

Likewise, in Examples 1, 2 and 3 and in similar embodiments of suchmethods, the amount of modifying agent (metal salt, etc.) may be varied,as disclosed in my prior Ser. No. 359,425; for instance, varied from say2 to 10 per cent on the resin material being modified. In all cases,modified resins useful in making varnishes are obtained.

Thus as shown ante, I can produce modified products useful in makingvarnishes and lacquers'from fatty oils or resins or both; and some timesI use a mixture of fatty.. oil and resin (rosin, etc.) as the startingmaterial and simul-' taneously modify both by my methods.

In anyof the methods described ante, metal salts may be employed withadvantage, as illustrated ante. Further, as there shown, some metalsalts have particular advantages. For instance, excellent varnish basematerials can the fatty 'oil and resin tion in pressure tends tointensify in my processes.

be obtained from resins with the aid of the following metal salts:

Magnesium sulphate Sodium sulphide Ammonium iodide Magnesium carbonateZinc carbonate Leadcarbonate The last three of the above-mentionedsalts, are difiicultly soluble in water. And the modified resin productsmade with these salts have superior properties. For instance theso-modified resin products are resistant to water and -may beadvantageously employed in making water-fast varnishes. Likewise, othersalts which are insoluble or difiicultly soluble in water be treatedaccording to the present process, dry-' ingoils and semi-drying oils maybe used in case paint and varnish raw materials are made by theprocesses. On the other hand, in case of lacquer:

raw materials, non-drying oils may be added to the resins. Also fattyoils, fatty acids, waxes, asphalt, as halt. oils, tars, tar oils,pitches'and other similar products may be mixed with the resins beforeor during treatment according to the present process.

The products of the reaction vary in the case of any one definitestarting material according to (a) Variations made in the nature of themodifying agent.

(b) The percentage of the modifying agent used.

(c) The duration of heating.

(d) The reaction temperature.

(e) The nature and physical state, pressure, of

' the gas present in the reaction chamber,

etc.

The reaction may be further influenced. by irradiation with short-waveoscillating energy,

, ultra-violet rays, X-rays, etc.

The modifying process may be accelerated, not only by radiations asmentioned in the pr. or specification, but also by making'the mixture ofstarting material and electrolyte part of anelectric circuit:

Likewise, I have found that the presence of air or other gases somewhatalters the results obtained. For instance, the products obtained byheating in the presence of air are somewhat different from thoseobtained when the mixture is heated in contact with other gases, such ascarbon dioxide, nitrogen, hydrogen sulphide, sulphur dioxide, etc., ormixtures of gases. It may .be stated with reference to theaction ofgases that, generally speaking rarification of the gases present in thereaction chamber by the reductheir action In my present processes,treatment in conjunction with the modifying action of the modifyingcompounds. The gas treatment may be carried out by blowing the gasthrough the reaction mixture or simply by passing it over the masscontained in the reaction chamber. For this purpose I may employ activeor inert gases. In doing so, I find that CO2, nitrogen, hydrogensulphide and S02 are advantageous. Further, the gas may be produced insitu in the reaction mass by using substances which under the conditionsof the reaction develop thetdesired gas, such, for instance, ascarbonates, sulphides, sulphites and the like, all of which developcorresponding gases in the reaction mass.

Likewise, if desired, the modifying be produced in situ within the massunder treatment.

The addition of a small amount, generally not more than 5 per cent onthe'weight of the start- I may employ a s eluding esters thereof, (3)esters of ing material of 'auxiliarysecondary purely organic metal-freereagents such as aldehydes, phenols, alcohols, ketones, hydrocarbons,etc., may have favorable results.

It-isfurther possible to use the above described .reagents, in'combination withany modifying agent described in any one of the abovementioned specificationse. g. with organic or inorganic acids, withsalts, with organo-metall ic compounds, with amino compounds, withcompounds comprising within the molecule an acidic inorganic residue andan organic residue (viz. my application Ser. No. 359,425 and Ser. No.318,650).

By an acidic inorganic residue, I mean such an inorganic residue as canbe converted by the addition of one or more hydrogen atoms or by theaddition of one or more molecules of water, and/or by the action ofelevated temperatures into an inorganic acid (including carbonic acid,as inorganic), leaving the organic residue behind. It will be seen fromthe above definition and from the illustrative compounds disclosed in mySerial No. 359,425, that this'generic class of modifying agents includessuch compounds as (1) organic halogen derivatives, (2) organic sulfonicacids and their halides and salts, in-

inorganic acids, (4) inorganic salts of organic bases and (5) organicnitro compounds, etc. amples illustrative of each of these classes aregiven in my said Ser. No. 359,425, (U. S. Patent 2,213,944). Some of themodifying agents specifically disclosed in that application areillustrative of other classes of modifying agents useful in myprocesses. "That is, they contain a plurality of constituents, groups orradicals irnparting polarityto such compounds.

As stated in prior specifications the application of an electricpotential within the reaction mass influences favorably the reaction.

I have further discovered that the dissolution of the modifying agentsin the starting materials maybe appreciably facilitated by the additionof certain auxiliary agents or sensitisers. These fall into two groups,namely, the purely inorganic (e. g., silica gel, fullers earth), and thepurely organic, e. g.: 1

The specific examples of auxiliary agents here mentioned are to be takenas typical of the subagent may Many exy stances which have beensuccessfully used for this purpose and not as comprising all theeffectice substances. It should be mentioned that some electrolytes, andquite a number of the modifying agents disclosed in priorspecifications, and containing an acidic inorganic residue and an'organic residue in the molecule, act as auxiliary agents (sensitizers)when used in conjunction with other modifying agents.

Thus, Within the scope of the present invention, I may prepare mymodified resins in various ways as shown ante. lustrative embodimentspreviously described, other embodiments may be used in the practice ofmy invention, in accordance with the description thereof given in thisspecification.

In modifying resins by the present invention, the physical and otherproperties of the resin are modified with the aid of metal salts andother modifying agents, as shown ante. The altered properties of themodified resins so obtained are due to complex, complicated changes intheresin system. Accordingly, the exact mechanism by And in addition tothe ilwhich the modification is effected is not fully known.

However, some of th'ose changes are undoubtedly colloidal in nature. Forinstance, the modification of the melting point and other physicalresins is decreased when such resins are modified by mypresentprocesses. Thus, a portion of the resin acids may be neutralizedor decarboxylated during such processing.

For instance, in modifying wood rosin according to the method describedin Example 2', the acid value of the wood rosin drops from 165 tobetween 60-80; the modified rosin so obtained being less acid than theoriginalv wood rosin.

Further in'such processes, I have also discovered that CO2 -issimultaneously given ofi during the Process. This indicates that eitherthe acid resin or the modified agent or both may be partially decomposedduring such modification. For instance, the zinc carbonate may decomposein such a way as to neutralize a portion of the resin acids and formsomezinc resinate, in situ, together with some CO2, when the mixture isheated under the conditions described in Example 2.

Such inter-reaction between part of the resin and zinc carbonate woulddecrease theacid value 01' the modified resin. Likewise, the zincresinate formed in situ would facilitate a further modification of theresin; it also beirig a metal salt. In fact as disclosed in my priorapplications, metal 1 ma volatile solvent.

resin products in such lacquers containing a sol-,

And perhaps both of the above mentioned changes occur during theseprocesses. In other.

words, the reduction in acid value and other modifications obtained maybe due in part to a neutralization of some of the resin. acids and inpart to a decarboxylation of another portion of the acid resin. Also,further changes in the resin nisms involved in modifying resins by myprocesses, I have found that such processes produce modified resinproducts having improved advantageous properties. And by the presentprocesses, hard resins can be converted intosoft res-' ins or liquidresins; the meltin point and viscosity of the resin being decreased whenso modi- -fied. Further, the reduction in viscosity so obtained is alsomanifest when these soft or;liquid resin products are dissolved involatile organic solvents. That is, the viscosity of their solutions insuch solvents is less than of a similar solution of the original resin.This is important in preparing varnishes, lacquers and other liquidcoating compositions containing volatile organic solvents.

My modified resins have other advantages in such compositions. Forinstance, my plastic or liquid resin products yield more elastic filmsthan do the untreated resins, namely, the original resin from which theyare prepared. That is, coatings containing such odified resins haveimproved elasticity as compared with a similar coating containing theoriginalresin.

In the case of lacquers, the elasticity of the film is particularlyimportant. Accordingly, my soft and liquid resin products can be usedwith advantage in making nitrocellulose lacquers and other lacquerscontaining cellulose derivatives, such as cellulose esters and ethers,etc., dissolved By incorporating the said For instance, nitrocelluloselacquers must contain a plasticizer in addition to the nitrocellulose asa film-forming ingredient. In such lacquers,

various liquid plasticizers have been used. When elasticity of the filmis improved, it is achieved usually by increasing the proportion of theplassalts of organic acids, including metal soaps, are

useful as modifying agents in my rocesses.

On the other hand, some of the resin acids may be decarboxylated duringthe heating in the presence of the metal salt. Likewise, this woulddecrease the acid value of the modified resin so obtained. That is, someof the acid groups may be split'o'fldurlng such heating; the acid groupbeing. decomposed withformation of CO2 in situ.

act. I, have observed a simultaneous develop- 'er thancarbonates areused as the modifying, .agejnt. Therefore, apparently a definitedecarboxylation occurs-during my processes.

t. of CO: in my processes wherein metal salts.

ticizer. However, when their proportion is increased over a distinctlimit, the liquid plasticizers known in the art cause the coating to becheesy and unsatisfactory. Below that limit,

the flexibility obtained may not be satisfactory. To avoid suchdiificulties, it has been proposed to use solid plasticizers. Forinstance, .various' vantageous properties to the lacquer. In otherwords, the incorporation of my modified resins in such lacquers givesseveral valuable advantageous improvements.

The improved lacquers so obtained are advantageous coating compositions.They yield flexible films having satisfactory toughness and goodelasticity.

In making such improved lacquers and coatings, various modifiedresinproducts may be employed, both those obtained from natural andsynthetic resins. And' as shown ante, various synthetic resins can bemodified by my processes.

And as shown ante, natural resins can be readily converted into soft andliquid resin products. Likewise, resinous esters can be modified toproduce valuable modified resins having decreased melting point andviscosity. But in modifying resin esters by the present processes, thedegree and rate of liquefaction i usually less than in the case ofnatural resins and other acid resins. That is, esterifiedresins are morediflicult to modify and convert into soft and liquid resin products. I

Thus in making liquid or plastic' esterified resins, I may employtwo-step methods, instead of directly modifying them. An advantageousand convenient method is to first liquefy the acid resin and then reactthe modified resin so obtained with the other components of thesynthetic resin and thus produce the modified synthetic resin desired.For instance, as stated ante, my modified natural resins are capable ofbeing esterified with glycerine and other polyhydric a1 cohols, When soesterified and resinifie'd, they yield other valuable modified resinproducts. The following example is illustrative of uch two-step methodsof making modified synthetic resins.

Example 4 in turn,,- can be converted into other synthetic 5' parts ofglycerine to' 250 C. and held there' for 2 hours at atmosphericpressure, using a refiux condenser to prevent evaporation of volatileingredients. After the 2 hours are over, vacuum is applied instead ofthe refiux condenser and the reaction mixture is heated to 280 and heldthere for 1 hour to boil ofi water and excess of glycerine, besidesother volatile ingredients. The resulting product is a plastic resinwith improved weathering properties.

The above example illustrates the manufacture of a modified ester gumfrom my liquefied rosins. produced in a similar manner by using otherpolyhydric alcohols in lieu of the glycerine. Also, in lieuof theliquefied rosin obtained in Exampl e 2, other liquefied rosins may beemployed in the method of Example a.

Likewise my liquefied rosins may be converted into other valuablesynthetic resins. For inthey may be used in makingmosin-modi- -11 aleicyresins and rosin-modified phenolic "r isuch' modified syntheticresinsmay be ,prepared-byjsubstituting the liquefied rosins obtained bythe. present-processes, for the rosin Other modified resinous esters canbe employed in the processes known in the art for making rosin-modifiedmaleic resins and rosinmodified phenolic resins; the processingotherwise being the same as now employed in the art.

The liquefied rosin obtained in Example 2, ante;-

the present invention contain terpene hydrocarbons containing doublebonds in various positions. Therefore, they may be condensed with maleicanhydride to-obtain polybasic acids which,

resins useful in the arts.

The modified resin products obtained as described ante, may bevulcanized as such or in varnish solutions, as described in my priorspecifications. Further, they may be converted into emulsions and usedin the processes of my prior emulsion patents.

Metal soaps as described in my Patent No. 1,963,065 may be considered asmetal salts from the point of view of the present invention, andsuchmetal soaps or salts may be used in the present processes as themodifying agent.

The examples shown ante are illustrating the invention and the latter isnot limited to the examples described.

4 And my generic invention relates to processes 1 sulphites of metalsselected from the class consisting .of magnesium, zinc and the alkalineearth metals and characterized by the ability to develop a"gas otherthan oxygen upon the application of heat during the treatment of therosin, and heating the mixture out of contact with the atmosphere at atemperature of from 250C. to 350 C. until the resultant mixture, whencooled, is softened to a consistency between about that of cold fiow andabout that of viscous oil, the time of treatment further beingsufiicient to appreciably reduce the acid number of the rosin but notsuflicient to lower said acid number to a value below about 60.

2. The process of making a modified and softened rosin product fromsolid and brittle rosin, which process comprises incorporation in therosin .up to 10% of a metalsalt selected from the class consisting ofcarbonates, sulphides and sulphites of metals selected from the-. classconsisting of magnesium, zinc and thealkaline earth metals andcharacterized by .the ability to develop a gas other than oxygen uponthe application of'heat during the treatment of the rosin, andheatingthe mixture out of contact with the atmosphere at a temperatureof from 250 C. to,

350 C. until the resultant mixture, when cooled, is softened to aconsistency between about that of cold flow, and about that of viscousoil, the time of treatment further being suflicient to appreciablyreduce the acid number of the rosin 4 which the metal salt is asulphide.

which the metal salt is a sulphite.

but not sumcient to lower said 1 acid numberto a value below about 60,

3. A process in accordance with claim 2 wherein the heating is carriedout under vacuum.

4. A process in accordance with claim 2 in which the metal salt is acarbonate.

5. 'A process in accordance with claim 6. A process in accordance withclaim 2 in 7. A process in accordance with claim 2 in which the metalsalt is zinc carbonate.

8. A process in accordance with claim 2 in which the metal salt is usedin an amount up to 5%.

9. The process of making a modified rosin product having drying andfilm-forming characteristics, which comprises incorporation up to 10% ofzinc carbonate in rosin, and heating the mixture out of contact with theatmosphere at a temperature-of from 270 C. to 290 C. until about 60. I

10. A process in accordance with claim 9 in which about 5% of zinccarbonate is used.

11. A process in accordance with claim 9 in which the heating is carriedout under vacuum.

12. A modified rosin product produced in ac cordance with the method ofclaim 2 and having a consistency ranging from about that of cold flow toabout that of viscous oil, and an acid value substantially lower thanthat of the same unmodified rosin, but not below about 60, said productfurther having melting point and viscosity both appreciably" reduced ascompared- 0 with the same unmodified rosin and having dry-' ing andfilm-forming characteristics.

LAszLo AUER.

CERTIFICATE OF CORRECTION. Patent No. 2,511,200. February 16, 1-915.

LASZLO AUER.,

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring; correction as follows: Page 5,first column, line 9, for "Lead carbonate" read "Lead chromate; and thatthe said Letters Patent shouldbe read with this correction therein thatthe same may conform to the record of the case in the Patent Office.

Signed and sealed this 2nd day of November, A. D. 1915.

Henry Van Arsdale, (Seal) Acting Commissioner of' Patents.

